Unexpected Sudden Death Due to Recreational Swimming and Diving in Men in Croatia in a 14-Year Period

Coll. Antropol. 36 (2012) 2: 641 645 Original scientific paper Unexpected Sudden Death Due to Recreational Swimming and Diving in Men in Croatia in a 14-Year Period Zijad Durakovi} 1, Marjeta Mi{igoj Durakovi} 2, Josip [kavi} 3 and Marija Definis Gojanovi} 4 1 Institute for Anthropological Research, Department of Medical Anthropology and Epidemiology, Zagreb, Croatia 2 University of Zagreb, Faculty of Kinesiology, Department of Kinesiological Anthropology, Zagreb, Croatia 3 University of Zagreb, School of Medicine, Department of Forensic Medicine and Criminology, Zagreb, Croatia 4 University of Split, School of Medicine, Department of Pathology and Forensic Medicine, Split, Croatia ABSTRACT The article deals with 17 sudden deaths which occurred during recreational swimming and diving in men in Croatia in a 14-year period: from January 1, 1998 to December 31, 2011. The sample is taken out from the total number of 61 sudden deaths in men during or immediately after sport or recreational exercise. Included are also sudden deaths of 8 foreigners spending holidays at the Croatian Adriatic Coast. In all of them forensic medicine autopsy was done. Thirteen males from Croatia died during recreational swimming. Three of them were aged 15 29 yrs: one had signs of hypertrophic cardiomyopathy, the second suffered from chronic myopericarditis with left ventricular aneurysm, and the third had cardiomegaly and blood alcohol level of 1.7. Five were aged 30 64 yrs: four of them have suffered from coronary atherosclerosis and left ventricular hypertrophy of 15 18 18 22 mm, and one with left ventricular hypertrophy drowned suddenly, probably because of malignant ventricular arrhythmia. The fifth suffered stroke and drowned. Five elderly men, aged 65 85 yrs, have suffered from coronary atherosclerosis, myocardial fibrosis or myocardial scars, and three of them had left ventricular hypertrophy of 19 mm. Four males died during recreational diving. One aged 26 yrs drowned, at autopsy he had left ventricular hypertrophy of 17 mm. Three males were middle-aged: two had coronary atherosclerosis, two of them had a severe degree of coronary atherosclerosis and one had coronary atherosclerosis of medium degree but with myocardial fibrosis and left ventricular hypertrophy of 18 mm. Seven male foreigners died, five of them during swimming: two aged 30 64 and two aged 65 85. They all have had coronary atherosclerosis: one of them had an acute myocardial infarction of the posterior wall, and one hypertrophic cardiomyopathy as well. One middle-aged and one elderly man died during diving, and both had an acute myocardial infarction of the posterior wall. One elderly foreign woman died during swimming, she had coronary atherosclerosis and a myocardial scar. In Croatia, death rate during both swimming and diving in men aged 15 29 years amounted to 0.63/1,000.000 (p=1.0000); in those aged 30 64 it reached 0.56/1,000.000 (p=0.3698), and in those aged 65 85 it was 1.41/1,000.000 (p=0.1849). The death rate during swimming in men aged 15 29 amounted to 1.47/1,000.000 (p=0.9864), in men aged 30 64 it reached 0.35/1,000.000 (p=0.2245), and in those aged 65 85 it was 1.41/1,000.000 (the difference is significant, p=0.0472). The death rate during diving in men aged 15 29 was 0.16/1,000.000, and in men aged 30 64 the observed rate was 0.21/1,000. 000 (p=1.0000). Key words: men, recreational swimming, recreational diving, drowning, sudden death Introduction Physical exercise, if regular and controlled, has many beneficial effects, with very rare acute health complications. The most common reasons for sudden death during recreational physical exercise in persons aged under 30 yrs are congenital heart diseases, while in middle- -aged and elderly persons causes of death are arterial hy- Received for publication February 5, 2012 641

pertension and coronary heart disease, including sequels of cardio-metabolic syndrome 1 16. Cardiovascular diseases are responsible for possible but rare complications in sports activities 1 16, comprising also complications due to swimming or diving 17 23. The aim of this study is to analyze the prevalence and causes of sudden death in males due to recreational swimming and diving in Croatia. Sample and Methods In a period of 14 years: from January 1, 1998 to December 31, 2011, the total number of 61 sudden and unexpected deaths during or immediately after sport or recreational exercises in males of all ages in Croatia were registered. Seventeen of them were men who died in summer due to recreational swimming and diving: eight in June, one in July, six in August and two in September. At that time no Croatian woman died due to such activities. Forensic autopsy was done in each presented case. The data are a part of a retrospective study, collected from the whole population consisting of 4,500.000 persons from the registry of the Forensic Medicine Services and the Public Health Registry of Croatia. At the same time, eight foreigners died during recreational swimming: seven men and one woman. The statistical difference was calculated by using the chi-square test and the Poisson rates. Results In the mentioned period, 17 males in Croatia died during recreational swimming and diving: thirteen of them died during swimming and four during diving. Of those 13 persons who were engaged in recreational swimming, three were aged up to 29, five between 30 and 64, and five between 65 82 years. Among those engaged in diving, one was aged up to 30 and three were aged between 31 and 64. In the same period eight foreigners died during swimming and diving, most of them at the Adriatic Coast: five were engaged in swimming: three aged 30 64 and two aged 65 85. Two were engaged in recreational diving: one was aged up to 29 and one between 30 and 64. One woman aged 82 swam in the sea and died. Table 1 presents forensic autopsy findings in men who died during recreational swimming and diving in Croatia in a 14-year period. These lethal events occurred in summer time, and in each case all applied reanimation efforts were unsuccessful. Four men aged up to 29 years have been without any symptoms before the incident. The first, aged 29, swam in a swimming pool, suddenly collapsed and died. The autopsy finding revealed hypertrophic cardiomyopathy: the left ventricular wall reached 25 mm, with normal coronaries. The second, a school boy aged 18, swam and kept jumping into the sea, then suddenly collapsed and died. The autopsy finding showed chronic myopericarditis TABLE 1 THE FORENSIC AUTOPSY FINDINGS IN MEN WHO DIED DURING RECREATIONAL SWIMMING AND DIVING IN CROATIA IN A 14-YEAR PERIOD Age (years) 15 29 30 64 65 85 Swimming: CHD Croatians 4 5 Foreigners 2 2 Stroke Croatians 1 (drowned) HCM Croatians 2 Foreigners 1 CMP(a) Croatians 1 Diving: CHD Croatians 2 Foreigners 1 1 LVH Croatians 1 1 Legend: CHD = coronary heart disease; HCM = hypertrophic cardiomyopathy; CMP(a) = chronic myopericarditis with left ventricular aneurysm; LVH = left ventricular hypertrophy with left ventricular fibrosis and aneurysm of the anterior part of the left ventricle. The third, aged 19, swam in the sea and abruptly collapsed and died. The autopsy finding disclosed the whole heart enlargement of 450 g, pulmonary edema, bilateral pleural effusions, and serum alcohol level of 1.7 (2 nd to 3 rd degree of drunkenness). The fourth, aged 26, who was free-diving in the sea, suddenly disappeared under the surface, and was taken out a few hours later. The autopsy finding displayed left ventricular hypertrophy of 17 mm. Eight middle-aged men from Croatia deceased: five due to swimming and three due to diving. The first, aged 57, obese, swam in a lake, collapsed and died. The autopsy finding showed obesity, coronary atherosclerosis, diffuse myocardial fibrosis and myocardial infiltration by TABLE 2 THE DEATH RATES IN MEN WHO DIED DURING SWIMMING AND DIVING IN CROATIA IN A 14-YEAR PERIOD Age (years) Died during swimming Died during diving Total 15 29 3 1 6 3999 134 0.47/1,000.000 a 0.16/1,000.000 d 30 64 5 3 14 262 906 0.35/1,000.000 b 0.21/1,000.000 e 65 85 5 0 3 549 448 1.41/1,000.000 c a : b, p=0.9864; a : c, p=0.2245; b : c, p=0.0472; d : e, p=1.0000 642

fat tissue. The second, aged 33, swam in the sea, and suddenly drowned. The autopsy findings were typical for drowning, left ventricular hypertrophy of 15 mm, and punctate bleeding in the brain. The third, aged 52, swam in a river, all at once collapsed and died. The autopsy findings manifested enlarged total heart volume of 350 g, left ventricular hypertrophy of 18 mm, and coronary atherosclerosis with narrowing of all coronaries up to 70%. The fourth, aged 50, swam in a river and suddenly drowned. The autopsy finding exposed heart enlargement of 500 g, coronary atherosclerosis with stenotic coronaries and left ventricular hypertrophy of 22 mm. The fifth, aged 61, swam in the sea and suddenly drowned. The autopsy finding confirmed drowning because of stroke: hemorrhage in both cerebrum and cerebellum, and in the subarachnoid space, heart enlargement with left ventricular hypertrophy of 18 mm and diffuse coronary atherosclerosis. The sixth, aged 47, died due to recreational diving in the sea. The autopsy finding showed diffuse coronary atherosclerosis of a severe degree. The seventh, aged 60, died during recreationally diving in the sea. The autopsy finding registered diffuse coronary atherosclerosis of medium degree, myocardial fibrosis and left ventricular hypertrophy of 18 mm. The eighth, aged 60, was diving recreationally in the sea, and deceased under water. The autopsy finding showed severe diffuse coronary atherosclerosis. Five elderly men from Croatia deceased during recreational swimming. The first, aged 69, swam in the sea, and suddenly collapsed and died. The autopsy finding showed diffuse coronary atherosclerosis of a moderate degree and myocardial scar of the front wall. The second, aged 82, swam in the sea, abruptly collapsed and died. The autopsy finding presented medium diffuse coronary atherosclerosis, diffuse myocardial fibrosis and left ventricular hypertrophy of 19 mm. The third, aged 68, swam in a swimming pool, all of a sudden collapsed and died. The autopsy findings demonstrated the whole heart enlargement, left ventricular hypertrophy of 19 mm, diffuse coronary atherosclerosis with narrowed left descending anterior coronary artery for more than 75%. The fourth, aged 82, swam in the sea, and suddenly collapsed and died. The autopsy finding was diffuse myocardial fibrosis, coronary atherosclerosis of medium to heavy degree with myocardial scar of the anterior wall of the left ventricle. The fifth, aged 74, swam in the sea, then suddenly collapsed and died. The autopsy finding displayed severe coronary atherosclerosis, myocardial scar of the posterior wall and left ventricular hypertrophy of 19 mm. Out of 17 deceased persons from Croatia, 10 had left ventricular hypertrophy of 15 17 18 18 18 19 19 19-22 25 mm. Death rate for both swimming and diving in Croatia, in men aged 15 29 years, reached 0.63/1,000.000 (p= 1.0000); in men aged 30 64 it was 0.56/1,000.000 (p= 0.3698), and in those aged 65 85 it amounted to 1.41/ 1,000,000 (p=0.1849). The death rate during swimming in men aged 15 29 years reached 0.47/1,000,000 (p=0.9864), in men aged 30 64 it amounted to 0.35/1,000.000 (p= 0.2245), and in those aged 65 85 it was 1.41/1,000.000 (the difference is significant, p=0.0472). The death rate during diving in men aged 15 29 reached 0.16/1,000.000, and in men aged 30 64 it was 0.21/1,000.000 (p=1.0000). In this period, five male foreigners visiting Croatia died due to swimming: three were middle-aged and two elderly, two died due to diving, and one elderly woman died when swimming. The first, aged 47, swam in the Adriatic Sea in June 2001, and suddenly sunk. The autopsy finding showed spongious pulmonary edema, coronary atherosclerosis of medium to severe degree. The second, aged 57, swam in the sea, and all at once collapsed and died. The autopsy finding showed generalized atherosclerosis, severe coronary atherosclerosis, acute myocardial infarction of the left ventricle posterior wall, and left ventricular hypertrophy of 15 mm. The third, aged 63, swam in the sea and suddenly collapsed and died. The autopsy finding revealed generalized atherosclerosis, whole heart enlargement of 580 g, diffuse myocardial fibrosis and left ventricular hypertrophy of 25 mm. Two elderly male foreigners died due to recreational swimming. The first, aged 69, has suffered from arterial hypertension and died six months after cured stroke. He swam in the sea, then suddenly collapsed and died. The autopsy finding manifested generalized atherosclerosis of medium degree, the whole heart enlargement of 500 g, and left ventricular hypertrophy. The second, aged 74, swam recreationally in the sea, and suddenly collapsed and died. The autopsy findings were a spongious pulmonary edema typical for drowning, coronary atherosclerosis with narrowing less than 1 mm, a myocardial scar in the posterior wall, and left ventricular hypertrophy of 21 mm. Two foreigners died due to diving. The first, aged 48, was diving recreationally in the sea. The autopsy finding showed the whole heart enlargement of 350 g, coronary atherosclerosis of medium to severe degree, acute myocardial infarction of the posterior wall, the right side liquidothorax of 120 ml, and left ventricular hypertrophy of 15 mm. The second, aged 77, was also recreationally diving in the sea. The autopsy finding exposed an acute myocardial infarction of the posterior wall, enlargement of the whole heart of 450 g, diffuse myocardial fibrosis, and left ventricular hypertrophy of 15 mm. At that time one elderly female foreigner, aged 82, who has suffered from arterial hypertension, died during swimming. The autopsy finding showed spongious pulmonary edema, coronary atherosclerosis, myocardial scar of the posterior wall, and left ventricular hypertrophy of 22 mm. Discussion Sudden death in healthy persons engaged in physical exercise is rare. When cardiovascular incidents do occur during exercise, the most frequent causes are congenital or acquired heart or vascular diseases. A great number of persons with coronary disease engage in physical exercise, and only a few experiences any discomfort. These data are supported by the analysis of the health-related 643

condition of the Croatian population: the so-called healthy persons of both genders aged 65 84 have six diagnoses on the range 0 17, including cardiovascular diseases 1 13. Relative risk for cardiovascular complications seems to be higher in exertion than at rest. In young persons who died suddenly during physical exercise because of cardiac arrest ventricular fibrillation, in about 6% of the cases the cause remains unexplained. Besides the fact that the heart is not trained for such efforts, the role of coronary spasm and reperfusion could be perhaps taken into account in the pathogenesis of sudden death. Many possibilities exist in defining an exertion-related sudden death. The time period needed for the cardiovascular system to return to resting steady state varies with many factors such as the type, intensity and duration of the activity, along with the health status and physical condition of the individual. Thus it is not easy to define exactly what is an exertion-related death, and especially sudden death caused by exercise. There is an opinion that lethal events in swimming and diving mostly occur because of drowning but, in our experience, 13 people died due to swimming in 14 years. The primary reason for death due to swimming is an organic heart disease. One man aged 61 drowned in the sea because of stroke, and had a hemorrhage in both cerebrum and cerebellum and in the subarachnoid space as well, with heart enlargement, left ventricular hypertrophy and coronary heart disease. All other 12 died suddenly because of cardiovascular diseases: coronary heart disease in 10, and two younger ones because of hypertrophic cardiomyopathy, and one from chronic myopericarditis with heart aneurysm. Four of 17 Croatian victims died due to diving: one aged 26, had left ventricular hypertrophy, and others aged 47, 60 and 60 had coronary heart disease. Cardiovascular diseases may be, by some authors, responsible for a quarter of lethal events during diving 17 19. In our data, however, cardiovascular diseases are responsible for all deaths due to swimming and diving. What could be the main reasons for sudden death due to diving? According to some authors 18,19, there is a vagal origin of sudden death. There are two vagal reflexes that might be responsible for lethal events: the diving reflex and the reflex dealing with the fear-induced central nervous system reaction 18. The result of these stimulations could be diving bradycardia. In experiments when animals are threatened while diving, heart rate could be reduced to 2 to 6 beats per minute. Sudden vagal death could occur when the vagal cardiac nerves are stimulated synergically by two independent reflexes 18. If one suffered from a heart disease, the consequence of vagal stimulation during diving could be much worse and lead to sudden death. There are no written strategies for the reduction of those diving fatalities. That is why pre-diving medical check-up is necessary to avoid complications 17. Acknowledgements This study was supported by the Croatian Ministry of Science, Education and Sport, No. 196-0342282-0291 and 034-0342282-2325. REFERENCES 1. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, [KAVI] J, Coll Antropol, 26 (2002) 509. 2. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, [KAVI] J, Coll Antropol, 26 (2002) 239. 3. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, VUORI I, ^OROVI] N, KUVALJA S, KUVALJA D, [KAVI] J, DEFINIS GOJANOVI] M, Coll Antropol, 28 (2004) 271. 4. DURAKOVIC Z, MISIGOJ DURAKOVIC M, VUORI I, SKAVIC J, BE- LICZA M, J Sports Med Phys Fitness, 45 (2005) 532. 5. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, [KAVI] J, TOMLJENOVI] A, Coll Antropol, 32 (2008) 399. 6. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, [KA- VI] J, DURAKOVI] L, Coll Antropol, 33 (2009) 387. 7. DURAKOVI] Z, MI[IGOJ DURAKOVI] M, Coll Antropol, 34 (2010) 159. 8. 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IZNENADNA SMRT TIJEKOM REKREACIJSKOG PLIVANJA I RONJENJA U MU[KARACA U HRVATSKOJ U 14-GODI[NJEM RAZDOBLJU SA@ETAK U ~lanku je izneseno 17 naglih smrti u mu{karaca za vrijeme rekreacijskog plivanja ili ronjena u Hrvatskoj u vremenu od 14 godina: od 1. sije~nja 1998. do 31. prosinca 2011 g., od ukupno 61 mu{karca preminulog za vrijeme ili neposredno nakon tjelovje`be, iu7mu{karacastranaca i jedne strankinje. U svih je provedena sudsko-medicinska obdukcija. Za vrijeme rekreacijskog plivanja u Hrvatskoj naglo je umrlo 13 mu{karaca. Trojica su bili u dobi 15 29 g.: jedan je imao hipertrofijsku kardiomiopatiju, drugi kroni~ni mioperikarditis s aneurizmom lijeve klijetke, tre}i kardiomegaliju s koncentracijom etanola u krvi od 1.7. Petorica su bila su dobi 30 64 g.: ~etvorica su imala koronarnu aterosklerozu i hipertrofiju lijeve klijetke 15 18 18 22 mm, a jedan od njih naglo se utopio, vjerojatno zbog maligne aritmije klijetki, dok se drugi utopio zbog razvoja apopleksije mozga. Pet ih je bilo tzv. starije dobi: 65 85 g., a imali su koronarnu aterosklerozu, fibrozu miokarda, o`iljke nakon preboljelog infarkta miokarda, a trojica su imala hipertrofiju lijeve klijetke od 19 mm. ^etvorica su umrla za vrijeme rekreacijskog ronjenja. Jedan u dobi od 26 g. imao je hipertrofiju lijeve klijetke od 17 mm, dok su trojica dobi 30 64 g. imali koronarnu aterosklerozu, jedan fibrozu miokarda i hipertrofiju lijeve klijetke od 18 mm. Sedam je stranaca umrlo, od toga petorica za vrijeme plivanja. Trojica su bila u dobi 30 64 g. a dvojica u dobi 65 85 g., od ~ega su ~etvorica imala koronarnu aterosklerozu, jedan akutni infarkt miokarda stra`nje stjenke lijeve klijetke, a jedan hipertrofijsku kardiomiopatiju. Dvojica su umrla za vrijeme ronjenja: oba su imala akutni infarkt miokarda stra`nje stjenke lijeve klijetke. Jedna `ena starije dobi umrla je za vrijeme plivanja, imala je koronarnu aterosklerozu i o`iljak nakon preboljelog infarkta miokarda. Stopa smrti za vrijeme rekreacijskog plivanja ili ronjenja, u 14-godi{njem razdoblju u Hrvatskoj u mu{karaca dobi 15 29 g. iznosi 0,63/1.000.000 (p=1,0000); u mu{karaca dobi 30 64 g. iznosi 0,56/1.000.000 (p=0,3698) i u onih dobi 65 85 g. iznosi 1,41/1.000.000 (p=0,1849). Stopa smrti za vrijeme rekreacijskog plivanja u mu{karaca dobi 15 29 g. iznosi 0,47/1.000.000 (p=0,9864), u mu{karaca dobi 30 64 g. iznosi 0,35/ 1.000.000 (p=0,2245), a u dobi 65 85 g. iznosi 1,41/1.000.000 (razlika je zna~ajna: p=0,0472). Stopa smrti za vrijeme ronjenja u mu{karaca dobi 15 29 g. iznosi 0,16/1.000.000, a u mu{karaca dobi 30 64 g. 0,21/ 1.000.000 (p=1,0000). 645